Power hammers



F. GALVEZ 2,772,858

POWER HAMMERS Dec. 4, 1956 Filed April 25, 1955 s Sheets-$heet 1 FIG.|

28 INVENTOR.

FRANCISCO GALVEZ ATTORNEY.

F. GALVEZ POWER HAMMERS Dec. 4, 1956 Filed April 25, 1955 3 Sheets-Sheet 2 INVENTOR. Famcusco sALvEz ATTORNEY.

Dec. 4, 1956 v z 2,772,858

POWER HAMMERS I Filed April 25, 1955 3 Sheeis-S'neet 3 FIG. ll

FIG. IO

g. u s Q :32 N a. INVENTOR. FRANCISCO GALVEZ BY M ATTQR NEY.

I compression of the sp1jingjisj transmittabl'e betweenithe inertia member and the crank, The invention additionand :for continuously;isupplying water to thetool :cutting invention, refierence being had tforgthispurpose, to ;'the

V of r g; '4;

United States. PatentO 10 Claims. (Cl. 255- 39) ,f

This invention relates to; power hammers, and more particularly to power Zhammers ct mechanicaltype employing. spring recoihfor driving an inertia,mem ber.

In power hammersfof the type referred to, which are employed for rock drilling and similar;uses, .it has generally been the practice to employ compressed air for the driving force, ,Such devices, where use is required remote from the source of compressed air, require extended hose connections which are cumbersome, and result in low efiiciency. The present invention is directed toa mechanical hammer in whichthedriving power in the form of "an electric motor or other prime mover may form a part of and provide a direct drive; The invention is further directed to a powerhammer having highly efficient hammer driving mechanism operable by minijmum power requirements. Theinvention is directed to a power hammer wherein continuqus rotary movement is employed to repeatedly gcompress a spring, the; recoil of which drives the inertia hammer, member}. ,The in,-

vention is further directedgt-o a imechanical rotary. lost motion drive associated with a; crank for compressing the spring, which permit tthe crank to-freely accelerate with reference to the pri-me mover driven drivingmember,

in response to spring recoil, after passing topdead center position. The invention is further-directed to a mechanism in which springcompression isefiected by thefapiplication of continuously avail-able'steadypower, whereby compression and recoil occurs in rapidly, repeating cycles. Further the invention is directed tothe use of '3Hta11iCu lat-ed connecting rod betweenwthecrank and inertial member whereby no force .other, than tension during the actual ally is directed to -applying to, a mechanical hammer, means tor continuouslyrotating thehammerdriven tool,

d s as eq -15.;

. F The above and othernovel features of the inv'entionw-ill appear more fully hereinafter from the following detailed description, when taken .in conjunction with the accompanying' drawings. It is expressly understood that E the drawings are employed forypurposes of illustrationbonly and are not designed asia definition of the limits ofthe appended claims.

vIn 1 1c drawingssuwllerleinlik [reference char-acter-sindicate like parts: i .1 a 1* v V. s

, Figure 1 is an elevational view of thepower hammer; Figure 2 is-a sectional viewtaken .sub'stantia in, 124M Fig. 1;v Figure,-3;is a section vie,

lly, on] the n I ligure t isgian exploded ragmen iy se i m, F igur e"5 is an elevatiqnal.viewptthe.drivingme ber Figure 6 elev n J not subjected to tension.

2,772,858 Patented Dec. 4, 1956 'Figure 7 is :a transverse fragmentary sectional view taken substantially on the line 77. of Fig. 2; and

.Figures 8, 9, 10, and 11, are schematic views of the drive members and hammer-operating' linkage at successive phases of a cycle of operation.

,Referring to Figure 1, the power hammer is shown as having a tubular guide assembly 20, drive mechanism therefor located thereabove as at 22, amotor mounting sleeve 24, motor 26, and a tool 28 in the form-of a rock drill, projecting from the lower end. The motor mounting sleeve is provided with opposed handle bars 27. The guide assembly comprises a tubular member 30, having a flange 32 at its upper end integrally secured thereto, and a guide collar assembly 33 mounted at its lowe end.

As shown in Figure .2, thereis mounted on the flange 32 a U Ibearing frametsee also Fig. 3) having uprights 34 and '36, tied. together by a cross member 38, the uprights having laterally extendingfeet 40 and 42 which are secured to the flange 32 by bolts 44. Above the bearing frame is a plate 46 which is secured in spaced relation to the flange 32 by a plurality of bolts such as 48, each extending through a spacer sleeve as at 50,

such bolts being located adjacent the marginal edges of adjacent its marginal edge with an annular upwardly facing channelor groove 59, to receive the end of a coil spring '60, The upper end of the coil spring is seated in an annular seat 62, of a ring 64, which ring is bolted to the tubular member by a plurality of radial bolts such as 66 angularly disposed with uniform spacing around thetubular member 30., j

The frame members ,34 and 36 are provided with aligned and facing bearing cups 68 and 70 in which are positioned ball bearings 72 and 7.4, which receive the ends of a 'cr-ankshafit 76, uch shaft having a single crank throw 7'8. Thethrow 78 of the crankshaft carries a con,-

1 nectingrod 80, having a plurality of links 82, 84 and 8-6,

the links'82 and 84 lying on opp osite sides thereof, the bolt I being provided with a spacing collar 94 between the links82 and 84. The link 86extends into 'atransverse slot 96in the upper end of the hammer 5 2, andis pivoted on at-ransverse bolt 98. The threaded portion of each the bolt '88,- 9t) and 92 isbf'redirced diameter toprovid-eija Y shoulder against which the nuts 89, 91, an-d 93fare drawn,

. whereby to provide fixed spacing for the links pivotedon the bolts so as to provide free pivotal movement of thelinks with respect toione another. The links 82, 84, V

863a'i1dth'e connecting rod '8tb are of such a length as to ieadily-buckle in "the manner shown in Fig. 2, when the crankshaft'is at the lowposition, and the hammer head is resting on the upper facejlltlfl ofl'the [tool receiving collar 102, or inffact ;a't anytime when the linkage is' The-opposite'end's 104 and106 or thecra nksha ft 76am" provided with gear drive members 108 and" 110, eachiof which'i's freely rotatable on the respective shaft ends. Such'drive members each have circular facing recesses 7 112,-adapted .to,receive driven disc members suchas 114 and 116, which are keyed to the crankshaft and otherwise secured rigidly thereto as by welding, as is indicated at 118. The discs nest with slight clearance within the driven by the driving members 108 and 110. The pin are of .a diameter to freely travel the arcuate length of the slots, so that the discs may rotate ahead of aiidaccelerate in relation to the driving members. 108 and The gear teeth of the driving members 108 and 110 mesh withthe' teeth of pinions 1-30 and 132 fixed to the shaft 134, the ends of which are journa'led in ball bearings 136 and 138, received in bearing cups 140 and 142 an the frame uprights 34 and 36; The pinion 132 is pro vided with an integral bevel gear 144, meshingwith a driving bevel gear 146 mounted on a stub shaft 148. The stub shaft is journaled in a ball bearing 149 mounted in the cros member 38. The upper end of the shaft has an fixed thereto a gear 150 and a jaw clutch member 152. i The motor 26 has a shaft 154, the lower end of which has aifixed thereto a pump drive gear 156; and a jaw clutch member 158, the latter being keyed to but slidable axially of the shaft into and out of engagement with the jaw clutch member 152. The member 158 has a shifting collar groove 160, which is adapted to receive the forked ends 162 and-164 of a shifting lever 166, men lever extending through an aperture in the sleeve 24 and being pivoted on the plate 46 as at 168, and having a manual lever handle projecting laterally from the airparatus as at 170, conveniently located with respect to a handle bar 27;

With the gearing as shown, it will be seen that the (ll-iving members or gears 108 and 110 are adapted re be continuously driven at a substantially uniform speed by the motor 26, the speed being reduced by about /2 or mere by the .bevel gears and pinions 130 and 132 and genre 108 and 110, the pitch circle diameters being so chosen as to provide a speed of rotation of the driving members in the order of about 400 revolutions per minute. It will be seen that the crankshaft is adaptedto be driven by the 4 The spring recoil is thus free to accelerate the hammer and deliver a blow to the end of the tool 28. i

In Figures 8, 9, 10 and 11, the successive positions of the parts are illustrated at various stages of a single cycle of operation. In Fig. 8, the crank throw is at the bottom and about to be rotated upward by clockwise rotation of the slotted driving members 108 and 110. The links 80, 82, 84 and 86 are shown as buckled. The pins 124 and 126 are shown at the ends 128 and 129 of the slots 120 and 122. The hammer is at its lower end point of travel. in Figure 9 the driving members have rotated about 90 and carried the crank throw about half way to top dead center; The connecting rod and links are shown drawn taut in tension, and the hammer has been partially lifted, partially compressing the spring 60. In Figure 10, the spring has been fully compressed, the crank is at top dead center, and further rotation of the crank carries it beyond dead center, at which point, the compression of the spring is free to recoil and commences to accelerate the hammer downwardly. The crank is free to juinp ahead, and the connecting rod linkage is free to buckle and eifect a disconnection between the crankshaft and hammer. By the time the driving members have rotated about 60 further as shown in Figure 11, the

a hammer has delivered its blow. During such period, the

crankshaft has been free to float ahead of the movement of the driving members 108 and 1 10, the disc pins 124 and 126 being positioned at some point towards the forward end 6f the slots 1.20 and 122.

Continued rotation of the driving members 108 and 110 restilts intaking up the slack in lost motion, until the position ef the parts a ain reaches that generally indicated in Figure 8. p i

The lewei end 54 hi the hammer is adapted to reciprogate in a guiding sleeve 172, formed as a part of .a tool holding collar 102, slich collar 'having a thrust bearing flange 176,- and a toolgiii'din'g shank portion 178. The

sleeve is journaled within a collar 180 secured internally of the tubular member 30, by n series of radial bolts 132 disposed ciicninferentially with uniform spacing around the tubular member. Thefeollai 180 is provided with a bearing :slee've'184 for-the sleeve 172,- and nn annular downwardly facing shoulder 186. A thrust bearing 1.90

r is interposed between the shoulder 186 and flange 176.

The tool holder has an aperture 1 92eeaxia1 thereof for I receiving a tool 28, such aperture being of hexagonal or and 110, as seen in Fig. 2, the ends 128 and 12, of the slots will engage the pins 124 and 126 whereby the crank shaft 76 will be rotated from the low point shown, tofthe topijdead center position, the crank acting to take up the slack in the connecting rod'titt and links 82, 84 and 86, as the crank progresses in its rotation to the top dead center position. When the links are placed in tension, the hammer 52 is lifted, compressing the coil spring "60, which spring reaches maximum compression when the crank shaft reaches top dead center.

As soon'asthe crank shaft is carried beyond top dead 1 center, the compression of the spring 60 causes the-crank shaft to accelerate ahead of the driving members iiis and 110, the slots permitting the pins to angularly rotate ahead and accelerate. -At the same time, the connecting rod andartic'ulated linkage thereof relieve the crankshaft of any positive connection with the hammer, thelinkage I being free to buckle, and being incapable of transmitting any force between the crank and hammer other than ten sionf The slots are of suifricient arcuate length'so as to 9 provide complete freedom of the crankshaft during the "period of descent ofthe hammer, it being understood that 7 during such descent the driving members 108 'andf110 are also following along at ;a relatively :stadyangular velocity. For this reasonthe angular length of the slots;

to give complete freedom'duringitihe acceleratiohof the V hammer-on thedownstroke, need be about as shown:

poligonal configuration to receive the shank of the tool of'conrp'lementary cross section. The tool holder is retained in place by the flanged, end sleeve 194 secured as by'ser'ew's 196'to'th'e end of'th'e collar iso- Aflixed to the shank 178 is a helical toothed gear 291, by means of which the tool holderjis' rotated. Rotation is effected by a shaft'200 extending'alongsideithe assembly', such "shaftbeing' provided with a top bearing 26?. mounted on the plate 46, and a bottom bearing located in a bearing clamp 204 secured to the collar 180 as by screws 205-. The shaftis provided with a pinion 207 meshing with the gear at its upper end, and a pinion 206 meshing with the gear 201 at its lower end. The tubular member 33 isfent away as at 208'for this purpose. '7 i The 00128 m'avh'a've a bor'e'2-12 extending lengthwise thereof to provide a steady flow'of water to the lower euttingend 213 thereof, and the hammer 52 is provided with a bore 214 extendingfroma laterally disposed position'at the upper end to, the eenter'ni the head end.

puinp' 6f the gear type as at 216 is mounted on "the flange 32, and a flexible conduit 218connect's the outnew efii'he pump to the here 214', such flexible conduit extending. into the upper end of the tubular member 30,

102, the ring being adapted to engage the shoulder 223 at theend or the enlarges here us serve as a means for net limiting the tool position within the collar, with its upper end above the face 100 of the tool receiving collar. In practice, the upper end of the tool will be located about A" or more above such face to receive the repeated blows of the head end of the hammer.

In practice, a motor of one-half horsepower, three phase or single phase, may be employed to compress the spring for recoil hammer operation, and while an electric motor has been shown, it will be understood that any fractional horsepower prime mover may be mounted on the upper structure t0.drive the driving members 108 and 110.

It will be appreciated that the articulated connecting rod, in addition to severing all connection between crank and hammer during the recoil of the spring, also serves as a shock dampener when the crank commences to apply tension to the linkage to initiate spring compression, the

links upon being drawn taut, tending to cushion the shock. In practice, six or seven complete cycles of operation, or hammer blows, occur each second, and the weight of the apparatus is such as to absorb a substantial amount of the shock to the operator guiding the apparatus by the handles 27.

at The clutch members 152 and 162, when uncoupled,

stop the rotation of the tool. The pump, however, is continuously driven to supply a flush of water, so that the rockthole being drilled by the tool may be flushed at will, without necessitating the concurrent operation of the hammer.

While the invention has been shown in its direct application and in a single embodiment which has been illustrated and described, it is to be understood that the invention is not limitedthereto. As various changes in the construction and arrangement may be made without departing from the spirit of the invention, as will be apparent to those skilled in the art, reference will be had to the appended claims for a definition of the limits of the invention.

What is claimed is:

1. power hammer comprising a reciprocating inertia member, a frame'including a guide way for said member,

a coilspring having one end bearing against said inertia member, and the other secured within said guide way, a single throw crank shaft extending transversely of the axis of movement of said member and journalled on said frame beyond the other end of said coil spring and on opposite sides of the axis, an articulated connecting rod connecting the throw of said crank shaft with said inertia member to compress said spring said rod being composed of at least three links serially and pivotally connected on axes parallel with said shaft, rotatable driving means freely rotatable on said crank shaft, means providing for limited relative angular movement between said driving means and crank shaft whereby said crank shaft'may accelerate in reference to said driving means in i'esponse'to spring recoil, and power means for rotating said driving means at'a substantially uniform angular velocity.

2. A power hammer comprising a reciprocating inertia member, a frame including a guide way for said member, a coil spring having one end bearing against said inertia member, and the other secured within said guide way, asingle throw crank shaft extending transversely of the axis of movement of said member and journalled on said frame beyond the other end of said coil spring,

power means for rotating said driving means at a substantially uniform angular velocity, and means for holdinga tool in alignment with said inertia member and in position to be struck thereby upon recoil movement thereof.

3. A-power hammer comprising a reciprocating inertia member, a frame including a guide way for said member, a coil spring having one end bearing against, said inertia member, and the other secured within said guide way, a single throw crank shaft extending transversely of the axis of movement of saidmember and journalled on said frame beyond the other end of said coil spring and on opposite sides of the axis, an articu lated connecting rod connecting the throw of said crank shaft with said inertia member to compress said spring said rod being composed of at least three links serially and pivotally connected on axes parallel with said shaft, rotatable driving means freely rotatable on said crank shaft, means providing'for limited relative angular movement between said driving means and crank shaft where- ,by said crank shaft may accelerate in reference to said driving means in response to spring recoil, powermeans for rotating said driving means at a substantially uniform angular velocity, means for holding a tool in alignment with said inertia member and in position to be struck thereby upon recoil movement thereof, and means including a connection to said power means for rotating said holding means.

4 A power hammer comprising a reciprocating inertia member, a frame including a guide way for said member, a coil spring having one end bearing against said inertia member, and the other secured within said guide way,=a single throw crankshaft extendingtransversely of the axis of movement of said member and journalled on said frame beyond the otherend of said coil spring, an articulated connecting rod connecting the throw of said crank t shaft-with said inertia member to compress said spring, said rod being composed of at least three links serially and pivotally connected on axes parallel with said shaft,

, rotatable drivingmeans freely rotatable on said crank shaft, means providing for limited relative angularmovement between said driving means and crank shaft whereby said crank shaft may accelerate in reference to said driving means in response to spring recoil, said means comprising an arcuate slot on one of said rotatable means and crank shaft, and a crank pin angularly rotatable therewithin on the other, and power means for rotating said driving means at a substantially uniform angular velocity.

5. A power hammer comprising a reciprocating inertia member, a frame including a guide way for said member, a coil spring having one end bearing against said inertia member, and the other secured within said guide way, a single throw crank shaft extending transversely of the axis of movement of said member and journalled on said frame beyond the other end of said coil spring, an articulated connecting rod connecting the throw of said crank shaft with said inertia member to compress said spring, said rod being composed of at least three links serially and pivotally connected on axes parallel with said shaft, rotatable driving means freely rotatable on said crank shaft, means providing for limited relative angular movement between said driving means and crank shaft whereby said crank shaft may accelerate in reference to said driving means in response to spring recoil, said means comi prising an arcuate slot on one of said rotatable means and crank shaft, and a crank pin angularly rotatable therewithin on the other, power means for rotating said driving means at a substantially uniform angular velocity, and means for holding a'tool in alignment with said inertia member and in position to be struck thereby upon recoil movement thereof. a

6. A power hammer comprising a reciprocating inertia member, a frame including a guide way for said member, a coil spring having one end bearing against said inertia member, and the other secured within said guide way,

and pivotally connected on axes'parallel with said shaft,

rotatable driving means freely rotatable on said crank shaft, means providing for limited relative angular movement between said driving means and crank shaft whereby said crank shaft may accelerate in reference to said driving means in response to spring recoil, said means comprising an arcuate slot on one of said rotatable means and crank shaft, and a crank pin angularly rotatable therewithin on the other, power means for rotating said driving means at a substantially uniform angular velocity,

means for holding a tool in alignment with said inertia member and in position to be struck thereby upon recoil movement thereof, and means including a connection to said power means for rotating said holding means.

7. A' power hammer comprising a tubular guide way, a bearing frame mounted at one end thereof, a reciprocating inertia member having a head end located in said guide way adjacent the other end thereof, a coil spring having one end anchored within said tubular guide way adjacent said bearing frame and the other end bearing on said inertia member, a single throw crank shaft journalled in said bearing frame and extending transversely to and across the axis of said guide way and supported on bearings on opposite sides of the axis, an articulated multiserially connected link connecting rod having at least two pivotal joints extending transversely of the guide way axis connecting the crank shaft throw and said inertia member *andextending through said spring-for compressing said spring,- driving means journalled on said crank shaft having limited relative angular movement with respect to said crank shaft whereby said crankshaft may accelerate free of said driving means in response to spring recoil, power means for driving said driving means at a substantially uniform speed, a tool holder journalled in the other end of said guide way beyond said inertia member and having an aperture therethrough coaxial with said guide way for receiving the shank of a tool with its end adapted to be struck by said head end, and gearing connecting said power means with said tool holder to rotate the latter.

8. A power hammercomprising a tubular guide way, a bearing frame mounted at one end thereof, a reciprocating inertia member having a head end located in said guide way adjacent the other end thereof, a coil spring having one end anchored within said tubular guide way adjacent said bearing frame and the other end bearing on said inertia member, a single throw crank shaft journalled in said bearing frame and extending transversely to the axis of said guide way, an articulated connecting rod connecting the crank shaft throw and said inertia member and extending through said spring for compressing said spring, said rod being composed of at least three links serially and pivotally connected on axes parallel with said shaft, driving means journalled on said crank shaft having limited relative angular movementwith respect to said crank shaft whereby said crank shaft may accelerate free of said driving means in response to spring recoil, said driving means comprising a member journalled freely on said crank shaft having an arcuate slot thereon and a crank pin fixed to said crank shaft extending into said slot, power means for driving said driving means at a substantially uniform speed, a tool holder journalled in the other end of said guide way beyond said inertia member and having an aperture therethrough coaxial with said guide way for receiving the shank of a tool with its end adapted to be struck by said head end, and gearing connecting said power means with said tool holder to rotate the latter.

9. A power hammer comprising a guide way, a reciprocating inertia member located therein, a spring for recoil driving of said member, a crank shaft having a throw journalled transversely of said guide way at one end of said guide way, an articulated connecting rod extending between said crank shaft throw and inertia member adapted to compress said spring preparatory to recoil driving of said member, said connecting rod comprising a plurality of short links pivoted serially together on axes parallel with said crank shaft, and driving means for said crankshaft comprising a driving member freely rotatable on said crank shaft having an arcuate slot, and a member afiixed to said shaft having a crank pin projecting into said slot whereby to. provide relative angular lost motion between said driving member and crank pin member confined to the arcuate length of said slot whereby said crank upon passing top dead center may accelerate with respect to said driving means in response to spring recoil driving of said inertia member.

10. A power hammer comprising a tubular guide way, a bearing frame mounted atone end thereof, a reciprocating inertia member havinga head end located in said guide 7 way adjacent the other end thereof, a coil spring having one end anchored within said tubular guide way adjacent said bearing frame and the other end bearing on said inertia member, a single throw crank shaft journalled in said bearing frame and extending transversely to the, axis of said guide way, an articulated connecting rod connecting the crank shaft throw and said inertia member and extending through said spring, for compressing said spring, said rod being composed of at least three links serially and pivotally connected on axes parallel withsaid shaft, driving means journalled on said crank shaft having limited relative angular movement with respect to said crank shaft whereby said crank shaft may accelerate free of said driving means in response to spring recoil, an electric motor mounted above said frame with its shaft aligned with said tubular guide way, and gearing between said motor shaft and driving means.

References Cited in the file of this patent UNlTED STATES PATENTS 

